Question

Define mixture, solution, and element

Answer 1

A mixture is something you can separate into its parts mechanically, like mixed nuts or sand.
A solution is something you cannot separate into its parts mechanically, like juice or root beer. Solutions are composed of two types of parts: Solvents, which do the dissolving (water is known as the "universal solvent" because it dissolves most things) and solutes, which are dissolved (like sugar).
Elements cannot be separated into anything further, they are the building blocks of our entire universe (In actuality, they can be broken down into subatomic particles such as protons, neutrons (which can be broken down into quarks and gluons) and electrons, but that's beyond the scope of this question)

Answer 2

Spot on ^^